This invention relates to piles used in offshore areas, and more particularly to a method of protecting piles used in areas having a mud layer susceptible to movement from the forces that the mud can exert against the pile.
In some parts of the world, conditions exist which cause great masses of mud to be deposited on the ocean floor. Principally, these deposits are the result of silt, organic matter and other earthen material being deposited at the mouths of large rivers, such as the Mississippi River. Due to the slope of the ocean floor and the continual deposition of new mud, these large masses of mud are unstable, resulting in continual shifting or moving of the mud or intermittent mud slides triggered by storms or other disturbances.
In some areas off the Gulf Coast of the United States, where large oil and gas deposits exist, the mud may be as much as 200 feet thick. These hydrocarbon deposits are conventionally developed from fixed drilling and production platforms supported upon piles extending through the incompetent mud layer and imbedded into the underlying competent bottom. The movement of this mud results in large forces being exerted on these piles; and, in fact, pile-supported structures in the Mississippi River Delta have toppled, apparently the result of mud slides.
Thus, while a need exists for a method for protecting piles from the forces produced by the movement of mud along the ocean floor, and the bottom of other water bodies, no satisfactory method for protecting these piles or for reducing these forces has heretofore been proposed.
Accordingly, a principal object of this invention is to provide a method for protecting a pile used in offshore areas having a layer of mud susceptible to movement overlaying a competent bottom from the forces that the mud can exert against the pile.
Yet another object of this invention is to provide a method for reducing the forces exerted by mud moving against a pile extending through the mud and imbedded in the underlying competent bottom.
A further object of this invention is to provide a method for increasing the fluid content of the mud adjacent to a pile extending through the mud and imbedded in the underlying competent bottom.
Other objects and advantages of this invention will be apparent to those skilled in the art from the following description.